我正在学习 Java初学者课程……由于某种原因，我的最新作业似乎非常困难。任务集中在文件 I/O 上。它涉及很多部分，但这部分是真正让我感到困惑的部分。它涉及：
- 读取销售文件，其中每行应该首先包含部门（N、S、E 或 W），然后是下一行的季度 (1-4)，然后是第三行的销售额，然后重复。（可以这样做）
- 我们必须验证每一行是否具有允许的选项/文件类型之一（可以这样做）
- 然后将任何错误转储到错误文件并要求用户提供另一个文件并重复，直到输入文件的格式正确。 （有这个工作）
- 一旦它采用正确的格式，我们必须能够生成以下格式的销售报告（无法弄清楚我应该如何能够收集到这个......）
销售报告
按部门划分的总销售额：
北 $total
南 $total
东 $total
西 $total季度总销售额：
一月至三月 $total
Apr-Jun $total
Jul-Sep $total
Oct-Dec $total年终总计：$total
一个菜单选项必须是验证文件格式是否正确，然后出现另一个菜单选项以生成销售报告。
注意：我们还不需要使用数组（这是下一个任务）。
import java.io.*;
import java.util.Scanner;
public class SalesReporting {
public static void main(String[] args) throws Exception {
String inputData;
String divisionRead;
int qtrRead;
double salesRead;
String filePath;
String menuChoice;
File fileName;
PrintWriter outputErrorLog;
PrintWriter outputSalesReport;
Scanner keyboard = new Scanner(System.in);
Scanner inputFile;
String overwriteFile;
Boolean isDataFileError;
Boolean isValidSalesFile = false;
Boolean isValidMenuChoice;
Boolean isToOverwrite = false;
System.out.println("\tHarmway Corporation" +
"\nQuarterly Sales Report Generator");
do {
do {
isValidMenuChoice = true;
// display main menu options to user & prompt for choice
System.out.print("\n\tMain Menu" +
"\n" +
"\n[V]alidate Sales Data");
// only display generate sales report option if a sales report has been validated
if (isValidSalesFile) {
System.out.print("\n[G]enerate Sales Report");
}
System.out.print("\nE[x]it program" +
"\n");
System.out.print("\nEnter choice: ");
menuChoice = keyboard.next();
if (!menuChoice.equalsIgnoreCase("v") &&
!menuChoice.equalsIgnoreCase("g") &&
!menuChoice.equalsIgnoreCase("x")) {
isValidMenuChoice = false;
System.out.print("\n\t**Error** - Invalid menu item");
}
} while (isValidMenuChoice == false);
if (menuChoice.equalsIgnoreCase("v")) {
do {
// prompt user for the sales data file path
System.out.print("\nSales data file path: ");
filePath = keyboard.next();
fileName = new File(filePath);
// if the file path doesn't exist, error displayed
if (!fileName.exists()) {
System.out.println("\n" + fileName + " not found");
}
} while (!fileName.exists());
// create a scanner for the input file
inputFile = new Scanner(fileName);
// create an error log to dump invalid sales data errors to
fileName = new File("errorlog.txt");
outputErrorLog = new PrintWriter(fileName);
// resets boolean to allow for error free data file check
isDataFileError = false;
// validate and store the sales data
while (inputFile.hasNext())
{
// first line must be division N, S, E or W to be valid
inputData = inputFile.next();
try
{
divisionRead = inputData;
if (isValidDivision(divisionRead)) {
System.out.println("ok division");
}
else
{
isDataFileError = true;
outputErrorLog.println(divisionRead + ",Invalid division value");
}
}
catch (Exception e)
{
isDataFileError = true;
outputErrorLog.println(inputData + ",Invalid division value");
}
// if second line is a valid quarter
inputData = inputFile.next();
try
{
qtrRead = Integer.parseInt(inputData);
if (isValidQuarter(qtrRead)) {
System.out.println("ok quarter");
}
else
{
isDataFileError = true;
outputErrorLog.println(qtrRead + ",Invalid quarter value");
}
}
catch (Exception e)
{
isDataFileError = true;
outputErrorLog.println(inputData + ",Invalid quarter value");
}
inputData = inputFile.next();
try
{
salesRead = Double.parseDouble(inputData);
if (isValidSales(salesRead)) {
System.out.println("ok sales");
}
else
{
isDataFileError = true;
outputErrorLog.println(salesRead + ",Invalid sales amount value");
}
}
catch (Exception e)
{
isDataFileError = true;
outputErrorLog.println(inputData + ",Invalid sales amount value");
}
}
// close the input sales data file
inputFile.close();
// close the error log file to write
outputErrorLog.close();
if (isDataFileError)
{
// there was an error in the sales file; not a valid sales data file
isValidSalesFile = false;
System.out.print("\nThe data file contains data errors"
+ " (See error log for details)");
}
else
{
// there were no errors; valid sales data file
isValidSalesFile = true;
System.out.print("\nThe data file is validated");
}
}
if (menuChoice.equalsIgnoreCase("g")) {
System.out.println("\ntemp g");
do {
// prompt user for file path to save sales report
System.out.print("\nSave report as: ");
filePath = keyboard.next();
// identify file to be used
fileName = new File(filePath);
// file already exists; ask whether to overwrite file or not
if (fileName.exists())
{
do
{
System.out.print("\nOverwrite (y/n): ");
overwriteFile = keyboard.next();
if (overwriteFile.equalsIgnoreCase("y"))
{
isToOverwrite = true;
// create printwriter for the sales data file
outputSalesReport = new PrintWriter(filePath);
System.out.println("\nGenerating sales report...");
// add code to write to the results to the file
// close sales report
outputSalesReport.close();
System.out.println("\nReport generated successfully!");
}
} while (!overwriteFile.equalsIgnoreCase("n") &&
!overwriteFile.equalsIgnoreCase("y"));
}
// file doesn't already exist; save the file
else if (!fileName.exists())
{
// create printwriter for the sales data file
outputSalesReport = new PrintWriter(filePath);
System.out.println("\nGenerating sales report...");
// add code to write to the results to the file
// close sales report
outputSalesReport.close();
System.out.println("\nReport generated successfully!");
}
} while (!isToOverwrite);
}
if (menuChoice.equalsIgnoreCase("x")) {
System.out.println("\nProgram has been terminated.");
System.exit(0);
}
} while (!menuChoice.equalsIgnoreCase("x"));
}
public static boolean isValidDivision(String divisionRead) {
if (divisionRead.equalsIgnoreCase("N") ||
divisionRead.equalsIgnoreCase("S") ||
divisionRead.equalsIgnoreCase("E") ||
divisionRead.equalsIgnoreCase("W")) {
return true;
}
else {
return false;
}
}
public static boolean isValidQuarter(int qtrRead) {
if (qtrRead >= 1 && qtrRead <= 4) {
return true;
}
else {
return false;
}
}
public static boolean isValidSales(double salesRead) {
if (salesRead >= 0) {
return true;
}
else {
return false;
}
}
}
我不是在要求具体的代码，而只是关于我应该如何最好地进行的一些指导。任何意见，将不胜感激。我已经被这个任务困了一个多月了！
如果采用有效格式，销售数据文件将是什么样子的示例（每个都在自己的行上......论坛忽略了中断）：
N
1
35.50
n
2
26.99
N
3
77.45
n
4
58.30
S
1
132.15
S
2
81.19
S
3
159.06
S
4
83.55
E
1
99.40
E
2
25.39
E
2
25.39
E
3
50.25
E
4
43.21
W
1
120.89
_
_
_
_
_
_
_
_
66.15
牛
3
38.22
N
4
27.66
E
2
135.32
E
3
37.50
E
4
9.10